I think we might not be on the same page here regarding the concept of "training".
"Training" is the planned process, by which measurable progress in skill is accomplished over time. In this context every single training session has a definite use. For a novice this definite use should always be to provide a stimulus for adaptation. One then rests until the adaptation has occurred and once this is, one got stronger.
To apply a new training stimulus, one cannot do the same again because the body already adapted to this. Therefore the stimulus needs to be varied in order to force further adaptation. The component of the work-out to vary here is weight on the bar.
Intermediate and advanced trainees cannot per definition make measurable progress in strength with a single work-out. For them work needs to be accumulated over a certain time in order to drive adaptation and make progress. The training stimulus then does not any longer consist of a single training session, but for example a week or even a month of training. They therefore can have a meaningful repetition maximum (rm), that has the attribute of being moderately stable. The same is not true for a novice. A novice does not have a repetition maximum that is moderately stable because every training session induces changes in this rm. Therefore you can forget about this concept altogether because it does not apply to you.
What you need to do is increase weight on the bar every time. And you start with a weight that you can do for 3 sets of 5 reps, in which you do not have to grind out the last set.
